Synthesis of La2Ti2O7 flexible self-supporting film and its application in flexible energy storage device

In this study, we succeed to synthesize the lanthanum titanate (LTO) flexible self-supporting film, and the flexible electrode based on the self-supporting film as active material were also provided to verify the electrochemical energy storage performance. The self-supporting film with both excellent flexibility and outstanding crystalline structure has been prepared by electrospinning combined with calcination method. To further optimize calcination processing, the microstructure, morphological characteristics and lattice structure of the self-supporting films can be explored by using SEM、TG、XRD and FT-IR. What’s more, the electrochemical properties of the flexible electrode prepared by LTO self-supporting film have been determined in various solutions. Comparing with the other aqueous, the highest areal capacitance of 806.2 mF cm−2 at 2 mA cm−2 was got form 1 M Na2SO4 aqueous electrolyte. Moreover, the symmetrical LTO//LTO flexible device fabricated by two LTO electrodes has a maximum areal capacitance of 149.2 mF cm−2 at a current density of 2 mA cm−2 with a high cell voltage of 2.1 V. As the result of that, this device exhibits a high energy density of 91.4 μWh·cm−2 at a low power density of 2.1 mW cm−2 with outstanding cycling life and excellent bending stability. Therefore, the LTO self-supporting film can be considered as a prospective material for wearable energy storage device.